Improvement in processes and apparatus for reducing ores



W. H. STERLING.

PROCESS AND A PPARATUSUF'OR REDUCING ons.

I 1 vcntor vPatented Nov-.'21, 187'6.

N.FETERS. PH0TOLITHO.GRM'ERl WASHINGTON. D. (L

UNTTED STATES PATENT EEi'cEo WILLIAM H. STERLING, OF SAN FRANCISCO, CALIFORNIA.

IMPROVEMENT IN PROCESSES AND APPARATUS FOR REDUCING ORES.

Specication forming part of Letters Patent No. l 84,554, dated NovemberQl, 1876; application filed August 14, 1876.

being had to the accompanying drawing.

My invention relates to an improvement in condensers or condensing apparatus for collecting and .condensing the volatile portions orV metallic fumes arising or generated in the roasting andf sinelting of metallic ores or compounds.

A furnace is constructed ofiron, linedwith Y tire-brick or clay, and shaped in the tapering form of a cone or pyramid. When the body of the furnace is constructed in the form of a pyramid, which I prefer, I place at appropriate points at each end and middle of the pyramid circula-r bands or cogs B B, which afford the necessary means of revolving` the'pyramid uponits axis. When the furnace is made in shape ofthe cone, then of course these bands are not necessary. These cogs or bands rest upon suitable revolving wheels C C, which give the furnace the proper revolutions. This pyramid or cone shape sloping body of the furnace is mounted upon these revolving Wheels in such amanner as to slightly incline or invert the pyramid or cone toward its smaller end,in order that in its revolutions the'oreJ may be slowly moved toward and discharged ont of its terminal end into the cooling or discharging chamber at that point. This inclination is effected by having the Wheels at the4 larger end of sufficiently greater diameter than those of the smaller as to overcome the difference in diameters, and thus give the incline or descent. At the base end of the pyramidal or conical body of the furnace is the usual fire-place with the most approved form of vmechanical devices for feeding the ore into the furnace. At the terminal end is an improved form of cooling and discharging chamber, consisting of a chamber with two discharge valves or gates at the bottom, so placed one above the other as to form a double bottom with a space of several feet betweenthem,

ot' a pyramid or cone are that, by such a shape,

the ore upon entering the furnace is very gradually heated, by reason of the heat loeing radiated over or throughout the Wide diameters at the base, and the ore distributed over a large surface; andy as the diameter of the pyramid or cone decreases, the ore simultaneously moving into the smaller space by the revolutions ofthe furnace, the heat is concentrated upon it and the ore becomes intensely hot, receiving all the benet of the concentrated heat, thereby effecting a great economy of fuel, and at the same time most thoroughly roasting the ore.

The action of this 'furnace combines the effectiveness of the reverberatory with the economy of manipulation of the revolving cylindrical. E

'The principleof action of this furnace being to concentrate the heat and ore simultaneously by a sloping or tapering form ot' furnace body, combined with a revolving motion given to it, the body ot' the furnace therefore may be constructed either conical or pyramid-al. That form which I prefer is a seven-sided or septangular pyramid, but it may be made in any polygonal form, or in that form which is very effective, a combination of the cone and pyramidal forms, such as that With the sloping or tapering sides of the furnace con.

structed alternately a cone and pyramid, one

side conical and the next side pyrainidal.

When it is desired to use the-furnace for chloridizing gold and silver ores I construct two man-holes or openings inthe body ofthe furnace for the purpose of adding the chloride of sodium or other chloridizing agent at the proper timewhen the ore is in the most suitable conditionvfor the chemical changes to nace is revolved very slowly about one-quarthe angular sides of the pyramidal body of` the furnace affording this facility ot' stirring the ore more after the effective manner of the reverberatory furnace than any other of those usually employed.

The essential part of my invention relates to a novel process `for aggregating the minnte particles of metals which do not possess sufficient specific gravity to cause them to settle. My said improved process also involves an improvement in the construction of coudensing apparatus for collecting and condensing the volatile metallic particles and fumes arising and generated in the process of roast ing and subliming metallic ores, and the escape of which, in the case of quicksilver subf limations, occasions so great a loss of valuable metal. l

i The very volatilenature of certain metallic fumes, such as those arising in the process of subliming quicksilver ores, renders them exceedingly` light and diffusible as infinitesimal atoms throughout the entire atmosphere of the furnace and condensing-chambers, be they ever so large or extended. These infinitesimal atoms of metal are in fact so diffusible that a large percentage, variously estimated from twenty to sixty per cent. of the whole amount Y or4 assay quantity originally contained in the Vin the reduction of quicksilver ores that not only are great losses sustained in the working ofhigh-grade ores, but the losses in the low grades are such that, in many instances, these latter ores cannot be profitably wor ked at all,

, even though they contain an assay quantity large `enough to be profitable if these large losses were not made, the loss being relatively larger than in high-grade ores, from the fact th at the metallic vapors arising from low grades are associated withja much greater relative proportion of atmospheric air, and consequentlythe metallic atoms are so much the :more diffused and so much the less condensible. With the object, therefore, of not only .cooling the metallic vapors `to the condensation-point, but also of subjecting' these infinitesimal and diffused atoms to the centripetal, rotary, spiral, gyrating, compressing, and whirling motions necessary to bring them into Mthe intimate and cohesive contact and aggregation required to produce a condensible-particle and metallic globule, I have devisedthe following novel contrivances, which substantially are thus described.

At the end of the outlet side of the ore-discharging chamber above described, or, if' preferred, atthe outlet of any ofthe condensingchambers heretofore in use, l place a series ot' refrigerating-surfaces, D DD, which are constantly flushed with cold water to `cool i the fumes, condense the metallic vapors, and wash down the soot, dust, and unredueed particles, of powdered ore. These cleansing-refrigerators are constructed substantially as follows: A chamber is formed ot' brick, wood, or clay lined iron Walls of the desired dimensions, the dimensions depending upon the size or capacity ofthe roasting-furnace, and quantity and quality of ore to be hourly treated.

In the interior of this chamber are arranged the cooling, cleaning, and condensing surfaces, Whieh consist of either hollow bodies, through which cold Water circulates, as represented, or solid bodies, over which cold water is passed. The most convenient form of these refrigerati11g-surfaces, and which I recommend as being economical in cost and effective for this purpose, is that of pipes D D,

made of earthenware, metal,ior wood. They may be made of any desired shape, either round, triangular, square, rectangular, or po lygonal. I have illustrated them in the drawings as heilig round, the ordinary ironstone earthenware being a very economical material for their construction. The exterior surface may be made rough or serrated, in order to break up the air-currents as much as possible, andthereby arrest and condense the metallic vapors, and give more surface for ,the collecting and washing down of' the soot and dust. If' pipes or hollow bodies are employed, a circulation is kept up through their interior of cold water, connections being made lfor that purpose outside the chamber. Solidbodies giving the same surfaces, however,may be employed, with their surfaces ,constantly flushed with cold Water'by the means hereinafter described; but I recommend that the hollow pipes, as illustrated, be used, as being economical in cost of construction and most effective. These pipes may be arranged in the chamber `either horizontally, perpendicularly, or diagonally; but I prefer the horizontal formas most convenient. They are placed, therefore, horizontally in rows, as seen in the accompanying drawings, one below or beneath fthe other, the number in each row being from six to ten, depending, of course, on the dimensions of the chamber. The drawing represents the front row as comprising six in number, which is about .the'ordinary number. These `pipes are placed horizontally, with a space of from one to three inches between them for the passage of thefumes or gases. Immediately behind these is arranged another lset in like horizontalmanner, but Withthe @sigaar a pipes directly oppositev the openings or spaces of the first set, and the openingsor spaces of the second set behind the solid portions or surfaces of the first, about one inchl space be-A ing between the two sets of pipes. They chamber is thus lled with pipes arranged in a similar manner, the solid portions or surfaces of each succeeding set being directly opposite the openings or spaces of the precedingv ones.

Toward the outlet of this refrigeratingchamber the pipes or surfaces may be placed closer together, in order that afterthe air-currents and vapors are cooled and cleansed ot' the soot and dust they may pass through smaller spaces and over or against still greater areas ot' solid surfaces.

At the top of each pipe or condensing-surface, and accompanying or running parallel to it, is a small tperforated pipe, G, which supplies a constantstream of cold water, by which, as it jets and flows over each pipe or surface,

the entire condensing-surfaces, t'ront and back.,v

are constantly iiushed with cold water and the chamber tilled with cold spray.

I. do not confine myself to any particular shape ot' these pipes or `condensing-surt'aces. They therefore may be 'made in any convenient or desirable form, and may be arranged horizontally, as illustrated in the accompanying draw-ings, or placed either vertically, diagonally, or in curves, the object and principle ot` the device being to so arrange the spaces or openings between the condensingsurfaces or pipes and their contiguity that each succeeding set maypresent a solid coldwater-hushed iront opposite the spaces ofthe preceding ones, and thus cause the currents of fumes or gases to break up and pass against and impinge upon the cold surfaces ofthe pipes or condensing bodies, and not escape actual contact, by having anywhere in the chamber a passage in a straight or ,direct curved line through the intervening spaces of the condensing-surfaces. A

Pipes or hollow bodies'with ,cold water cir culating through them may be used to present the necessary col'd surface,-without` the use ofy water-flushing theirexterior surfaces; but they are not so effective as when hushed as above described, from the reason that,'ay strong draft or current being produced, the air-currents from the furnace, laden with metallic vapors, soot, anddust, strike and Viinpinge upon some one of' these numerous coldwater-fiushed surfaces, andat once all dust,

soot, and nnreduced powdered ore are washedl down and the fumes ycooled to that pointwhich eondenses all the heavyor dense metallicparticles, leaving only the exceedingly subtle andv infinitesimal atoms to pass overv and be caught and condensed quent means employed.A Y'

After the vapors are thus cooled and washed by the refrigerators above described, they are passed into or through certain novel devices,

yby the subse,`

by which those very subtle and exceedingly diffusedl portions that may have passed over uncondensed are now subjected to the action necessary to cause cohesion and aggregation ofthe infinitesimal atoms, by which they may become a particle large enough to condense and fall from their own gravity. yI employ several devices to accomplish this purpose, and use them either in series or singly, as the case may be, the object of each being to give to the atoms that centripetal, rotary, spiral, gyrating, compressing, and whirling motion, and crowding together, required to form la condensable particle and metallic globule.

` I will describe in succession how they are constructed,A substantially as y follows First, about one to two feet from the last row of the refrigerating-surfaces are placed a series ot' pert'orated plates, screens, or diaphragms, HH

B H. These are placed upright, one succeeding the other, with a distance of from about two to three feet between them. They are in series, of about three to six in number to each series,'and the perforations in each succeeding plate or diaphragm are smaller than the preceding one. Thus, it' the iirst plate of the series has holes half-inch in size, then the last will have perforations one-sixteenth in diameter, the object and principle being to decrease the diameters or reduce the size of the holes of each succeeding diaphragm or plate, and thereby increase the pressure under or through which the metallic vapors must pass on their way outward. and by that means give the atoms of metal that revolving, compressing,'and centripetal motion, which conglomerates theminto a globule. These diaphragms are made ot' wood, earthen ware, iron,

or other suitable material; and, in order to still` further facilitate the inducing of the necessary revolving and compressing motions, they are made aboutvan inch in thickness, with their inlet apertures beveled, as represented at Fig. 3, forming a funnel-shaped passage-way through the plates.

To give the necessary facilities for removal andeXamination, they may be made in sections, and at the sides of the furnace may be constructed suitable openings, closed with airtight coverings. At the top of each plate is placed a perforated pipe, J, jetting a 'small stream of' water, by which the plate, is always kept clean and cold.

These diaphragms may be in one series, or several of such series may bei placed in succession in the same chamberora series ot'thenr l In order toA regulate the number of holes or areas of'` the diaphragms according` to the l amount of metallicr vapors passing from the furnace, and to maintain a greater orless pressure or exhaust in the chamberin which theplates or diaphragme Vare situated, several devicesmiay be employed. Those .two which I prefer as being the most convenient and practicable in ordinary use, and which -I use either one i IMI-@lu singly, or ythetwocombined, `are shutters' or movable partitions, marked t' t', `mounted upon hinges or pivots at the top or sides of the plates,` and swinging upon and closing a certain portion of the holes or apertures.` The otherv form is that of a mercury or water seal at the bottom ofthe perforated plates, the height of the Huid in the seal being regulated from the outside. This seal is made in rectangular form, withits sides about half the height of the plates, and about twelve inches wide. They may be made of woodor metal. The perforated diaphragms may be madeof any desired form, either square, circular, triangular, or polygonal; but the rectangular shape, as illustrated in the drawing, is convenientand desirable.

If desired, this control of the areas of the perforated diaphragm may also be accomplished by having the `diaphragms movable up and down in the seal by means of rods and weights; but I prefer the methods just described, as being the most convenient, economical, and practical manner ofusing them in quicksilver-condensers. The illustration of this device is seen in Fig. l.

y The next device which I shall describeas having the same desirable object of `giving the required centripetal and conglobing motions and consequent cohesion to the infinitesimal atoms, is substantially as follows: Iconstruct a double chamber, one within the other, or place within the continuation of the condensingchamber already described, an inner apartment. This inner chamber J is formed with six sides, each of the six walls being perforated with small holes with conical or beveled apertures one-fourth to one-sixteenth of an inch in diameter. The top is solid, and the bottom has an opening through which the vapors enter the chamber.

It being desirable, as in the case of the diaphragms just described, to control the areas of perforated holes, and to maintain a certain pressure or exhaust in the chamber, this inner apartment or ,vessel is fitted with certaincontrivances by which this object may be accomplished. l

These contrivances are as follows: e Within openings regulated, by an iron or wooden rod suitably fastened on a pivot or hinge, and passing outward through the sides of the inner and tho sidewalls of the outer chambers to theoutside, to` give `perfect control of the dimensions or` capacity` of this `inner 'perforated ,when it is desired to diminish the area` of the,r` chamber or perforatedholes one -halt',I the,` closing of these insideshntters against the,`

,jambA divides the chamberlintotwo` apartments, with the vapor-inlet inone only,and; the other apartmententirely, closed against the ingress ofvapors.,`

Another way in whichjhI maintain thiscer-l tain pressure or exhaust inthe chambeigand govern i the `number of lholes exposed to the passage of the vapors, is` byemploying a similar water or mercury seal as` described iin the device of perforated diaphragme, conforming the shape ofthe seal to the form ofthe cham-` ber, and l constructing it Ito a height half-way upthe sides of the chamber, and leaving a space of from six to twelvelinches between the sidesof the seal andthe chamber.` The height of the uid in, the. seal, is regulated from the outside, as in then case of the dia-I phragm-seals.

`I use either `one or both of these contrivances` forregulating the pressure oriexhaust, as may suit my convenience. w

This perforated chamber may beconstructed of any: desired shapeeither round, oval, cylindrical, circular, square, triangular, or polygonal-y-and the currents drawn through it by either an exhaust or suction fan, or forced by directlpressureof pum por pressure blower, the object being to canse the `vapors to pass, under a `certain pressure or exhaust force, with a revolving or gyratingmotion, `through the smallperforations in the sides or walls; but Ilprefer the six-sidedform as being the` most convenient and practical in accomplish; ing all of the objects of its construction.

\ The vapors, entering the inner chamber` through a ue atthe bottom, are forced to pass through the small perforations in the walls in order to gainaccess, to the outer space Ibetween, the inner and outer chamber, which forms the` tine or outwardpassageway. In thus passing through thesesmall perforations under pressure, the metallic atoms are revolved,` gyrated, crowded together, ,compressed, and adhere together, forming metallic particles, and fall from their ownweight or gravity, as metallic globules, to the bottom of the chamber.

The directionofthe currents through the perforated walls lorsides ot' theinuer chamber may be, as'thus described, from the chamber outwardwith the ingress-,flue at the bottom, or the reverse from the outside inward, with the egress or outlet flue at the bottom, whichever maybe most` convenient, the` object of the gyrations of the metallic particles being accomplished either way,. I` prefer, however, the currents to pass asdescribed, as giving a more perfectly uniform action upon` all sides 0f.. thech@-llflibr'` i, i

The shutters and water or mercury, seal mentioned give that control over the pressure upon the passing vapors by which, when the amount of.mercnrial vapors is small, the

capacity or dimensions of this device is diminished, and vice-versa.- Such inner shutters as described may be fitted to each wall or side ot' the chamber, if desired, and thus reduce the capacity to any desirable amount.

The next device to be described is the gyrating-tubes L, which consist of tubes about onefourth to one inch in diameter and one to three feet in length, constructed in such a manner as lto give a gyrating, rotary, and spiral motion to thevapor-currents passing through them. This may be accomplished by either bending or twisting the tubes spirally, or by making a screw-shaped gyrator, M, running centrally and longitudinally the whole length of the tube, which makes, in the plain tube, a spiral passage-way, through which the air currents and vapors must rotate on their passage outward. These tubes may be made of any suitable materialsuch as porcelain,`

earthenware, glass, wood, or iron-and may be placed at any desired angle; but I prefer them placed vertically, as illustrated in the drawings. The screw-shaped gyrator, in the longitudinal center of the tubes, may be made in two equal parts or lengths, with the thread or pitch ot' each haltscrew running in reverse directions, and forming, in the middle length ot' the tube, a chamber, in which the vaporcurrents are reversed and given an opposite gyrating or rotary motion from that in which they rst entered the tube. The ends of the tube may be iiared or expanded into a bell shape, so as to give free entry and free exit to the fumes, and aid in consolidating or compressing them together as they pass through the body of the tube. These gyrating-tubes may be with or without the gyrator in the center, the object ot' giving the spiral direction to the vapors being to induce, by the most rapid centripetal gyrating and spiral motions, a cohesion of the infinitesimal atoms, or mercurial vapor, as described, into a particle of sufficient size to be condensable by contact with a cold surface, and ot' sufficient gravity v to settle from the atmosphere ot' the condensing-chamber.

The tubes are placed vertically in series, each set or series being composed of any convenient number of tubes, With their inlets on' the same horizontal line and running in the same direction. The next set or series have their inlets on the same horizontal line as the outlets of the first, there being a suitable-partition between the two sets in the upper and At the top of the chamber in which these tubes are located, and directly over their ori tices, is placed perforated pipe or pipes, (not sho\vn,) supplying a small stream of water, by which the tubes are at' all times kept cool and free from dirt or dust. The number ot' orices kept open for the passage of vapors is regulated by means of a shutter or shutters swinging from a suitable frame at the top or sides ot' the tubes, and closing down and upon any number that may be desirable to close when the amount of vapors are small, and vice versa, and thus maintain a certain velocity or pressure ofthe vapors through the tubes. After passing through the gyrators or gyrating-tubes described, which may be in two or more sets, and placed either parallel or at au angle to each other, the vapors enter a set of conical or pyramidal shaped tubes, n a, about two feet in length, with the base orinlet ends about four to 'six inches in diameter and the outlets or nozzles from about one-fourth to. one-half inch in diameter. These may be arranged in plate N at any angle; but the horizontal form is preferable. These tubes may be made straight, with their orices brought to a point; but the conical or pyramid shape gives that compression and crowding together of the atoms better than a straight form, and therefore'is desirable. These may also have a screw-shaped or spiral gyrator placed in their longitudinal center similar to the gyrating tubes just described, with the exception that in this case the pitch or incline ot' the screw would not be reversed, but continued the same pitch, and decreasing in size until near the outlet, where the. screw would cease. These latter tubes may be made ot' any suitable material, such as wood, earthenware, or iron, and have the same contrivance ot' regulating-shutters as the previous device, controlling their inlet-apertures. The exhaustfan, producing the necessary rapidity and force of currents or draft, may be placed either between the refrigerating-chamber and the other devices described, or at the extreme outlet at the chimney, and a compensatinggovernor ot' approved construction may regulate the pressure or exhaust throughout the entire apparatus. I

These novel compressing, condensing, and

vapor gyrating or rotating devices above del scribed, being each in themselves complete, may be used in series, singly or combined, and may be applied to any one ot' the quicksilver-reduction ,works nowin use without any additional construction-expense beyond -that ot' their own cost. They can be readily placed at the outlet ot' the condensing-chambers now employed. This is a valuable feature ot' this invention, and one that can be appreciated by those who have already expended large sums of money in the erection of their works.

It will be seen at once that in this novel and valuable invention for collecting and condensing the volatile and diftusible mercurial vapors and metallic atoms I have departed entirely from the old and ineicientr methods. The old methods of condensing the very sub-` tlc and extremely diffusedV mercurial vapors are most unsatisfactoryand wasteful, and aftercenturies of experiment the losses, particularly in the reduction of very-loW-,grade ores, .are almost as great as when the science of metallurgy was in its rudimentary state, all the improvements hitherto attempted in this direction `heilig based upon the same unsound and non-scientific principle that all vapors or atoms of a substance of greater density,when in the bulk, than the atmosphere must, ot' ne` cessity, immediately condense and fall when brought into contact with a cold surface or coldatmospheric air; the fact in this connection, however, being that particles of metal or any other substance may beso volatilized and divided into such innitesimally small atoms i as to be as light and ditl'nsible as ordinary at'- mospheric air, and capable ot' floating with its currents to any'distance and for any ordinary length of time in the atmosphere.

The principle of construction applied in this within described condensing apparatus ac cepts this natural law and applies the true remedy for the great losses hitherto made by` the volatilization ot' metals in the process of their reduction. This consists, as aforesaid,

in the aggregation,conglomeration, compression, and cohesion of these infinitesimal atoms into a particle which shall beofsufcient size Witnesses:

Aanddensity to be condensable` and fall `by its own gravity. This aggregation and cohesion are' produced or induced by the refrigerating action and the rotating, gyrating, compressing, and condensing movements given bythe various devices employedin this invention, which throw together and bring into coni densable contact those diffused atoms,which,

under the old methods, escape from the condensers and float for an indefinite distance` upon the atmospheric currents.

Havingsthus described my invention, What I claim, and desire to secure by Letters Patent of the United States, is u l. In a metallic vapor-condensing device, the plates or diaphragms H H, provided with tapering perforations, substantially as set i forth. i

2. In a Quicksilver-condensing device, the extended tubes n, having contracted ends n', inserted 1n and in combination with the vertical partition N,lsubstantially as set forth.

3. The combination ot' the furnace, the ref` t'rigerating chamber and pipes, the perforated diaphragms, the perforated chamber4 or vessel, the gyrating tubes, the conical tubes, and straight tubes, all constructed and arranged substantially as herein set forth;

WILLIAM H. STERLING.

AOLWYN T. S'rA'oY, Geo. H. STRONG. 

